Prepare and heat charcoal or gas grill.
Soak wooden skewers in water for about 30 minutes.
In a large bowl, add chicken, zucchini, onions, bell peppers, mushrooms, balsamic vinaigrette, and garlic powder. Toss until all ingredients are combined. Add salt/pepper to taste. Cover and set aside for about 10 minutes.
Arrange ingredients on skewers and place on grill. Cook for approximately 10-15 minutes, or until chicken is thoroughly cooked and veggies are tender.
Nutritional Information (1 kabob): Calories 100, Carbohydrates 9g, Fat 0.5g, Protein 15g, Saturated Fat 0g, Fiber 2g, Sugars 6g